Search PubMed⌕ Search

Biomedical subjects

K Wiśniewski

Publications and source records attributed to K Wiśniewski.

At least 37 records · Page 2Linked to original sources
PubMed1998

Similarities and interactions between GABAergic and glutaminergic systems.

Harmonious interactions between neurotransmitter systems are important for regulating the activity in the central nervous system (CNS). gamma-Aminobutyric acid (GABA) and glutamate (Glu) are major inhibitory and excitatory neurotransmitters in the mammalian central nervous system. Neuronal excitability, probably synaptic plasticity, cognitive performance, learning and memory processes frequently the results of the balance of GABAergic inhibitory and glutaminergic excitatory inputs.

Animals↗
PubMed1998

Involvement of nitric oxide in cardiovascular effects of cholecystokinin (CCK) in rats.

UNLABELLED: The aim of the present study was determinate the role of nitric oxide (NO) in the action of CCK on arterial blood pressure and function of isolated rat heart. Intravenous administration of NO synthase (NOS) inhibitor-NG-nitro-L-arginine methyl ester (L-NAME-100.0 micrograms/kg) increased arterial blood pressure and abolished the hypertensive effect of CCK (administered in the highest dose: 425.0 pmoles/kg i.v.). Donors NO: L-arginine (L-Arg-100.0 mg/kg i.v.) and sodium nitroprusside (SNP-10.0 micrograms/kg i.v.) decreased arterial blood pressure, the hypotensive effect evoked by SNP was greater than produced by L-Arg. CCK administered with L-Arg evoked hypotension (opposite to the hypertensive effect evoked by CCK). When we used CCK at the higher doses (212.5; 425 pmoles/kg i.v.) simultaneously with L-Arg the hypotensive effect was greater than the hypotensive action evoked by L-Arg alone. Administration of CCK with SNP produced the hypotension (similar as after used SNP and opposite to the hypertensive action of the peptide). CCK (21.25, 42.5, 106.25 pmoles/0.1 ml) increased the cardiac contraction amplitude, the peptide injected in lower doses decreased coronary outflow. CCK had no effect on heart rate. L-NAME (10(-5) M) decreased coronary outflow, tendent to evoke bradycardia (p > 0.05) and the compound did not change the cardiac contraction amplitude of isolated heart. L-NAME abolished the influence of CCK on the function of isolated heart. L-Arg (10(-2) M) did not affect function of isolated heart. L-Arg abolished and when we used with CCK in the highest dose reversed the positive inotropic effect of the peptide and tendent to abolish a lowered coronary outflow evoked by CCK. SNP (10(-4) M) decreased the cardiac contraction amplitude. SNP diminished the positive inotropic effect of CCK and did not change other parameters of isolated heart. CONCLUSION: NO does not play a role in cardiovascular action of CCK directly, however inhibitor of NO synthase and donors of NO change the influence of the peptide, mainly on the heart. We suggest that the effect is indirectly through catecholamines.

Analysis of Variance↗
PubMed1998

Effects of sulfated cholecystokinin octapeptide and cholecystokinin tetrapeptide in rat behavior after blockade of nitric oxide synthase by L-NAME.

This study was conducted to determine what, if any, role L-NAME (inhibitor of nitric oxide synthase) plays in the behavioral effects induced by sulfated cholecystokinin octapeptide CCK-8) and cholecystokinin tetrapeptide (CCK-4) in adult male rats. The motility, stereotypy, anxiety, extinction of conditioned avoidance responses and recall of passive avoidance behavior were estimated. CCK-8 (but not CCK-4) injected intracerebroventricularly (icv) at the dose 0.1 nmole decreased of locomotor activity in the "open field" test. Administration of CCK-8 intensified stereotypy evoked by apomorphine (1 mg/kg, i.p.). The CCK-4 was ineffective in this test. Both, CCK-8 and CCK-4 did not make any significant differences in passive avoidance behavior. Examine the influence of CCK-8 and CCK-4 on the extinction of conditioned avoidance responses (CAR) proved that both peptide tended to facilitate extinction of CAR's. CCK-8 and CCK-4 induced anxiogenic-like effect in the elevated 'plus' maze behavior. Application of L-NAME alone (50 nmole,-icv) decreased of motility and stereotypy behavior in control rats. It was ineffective in a passive avoidance behavior and extinction of CAR's. In elevated 'plus' maze behavior injection of L-NAME, similarly to cholecystokinin, induced anxiogenic-like effect. L-NAME induced of motility decreases in the "open field" test were blocked by injection of CCK-8 and CCK-4. Our results indicate that observed behavioral activity of CCK-8 and CCK-4 (except of influence on motility) is probably independent of NO concentration in the brain.

Analysis of Variance↗
PubMed1997

Losartan influences behavioural effects of angiotensin II(3-7) in rats.

We have previously shown that angiotensin II(3-7) [Ang II(3-7)] stimulates behavioural activity of rats similar to angiotensin II (Ang II). The involvement of AT1 angiotensin receptors in stimulating the behavioural activity of rats, using their selective ligand losartan (DUP 753), was examined. Ang II(3-7), given intracerebroventricularly (i.c.v.) at a dose of 1 nmol, significantly enhanced recall of a passive avoidance behaviour, object recognition, learning of conditioned avoidance responses (CARs) and apomorphine (1 mg kg-1, i.p.) stereotypy. Losartan (1 microgram, i.c.v.) did not alter any of the behaviours except for that measuring anxiety which was diminished both, in peptide treated and in control rats. On the other hand, losartan abolished Ang II(3-7) facilitation of recall of the passive avoidance, object recognition and the increase in apomorphine stereotypy. Losartan did not influence the increased rate of CARs acquisition after the peptide. None of the treatments significantly changed locomotor activity estimated in an open field. These data point to some involvement of AT1 angiotensin receptors in the behavioural activity of Ang II(3-7).

Angiotensin II↗
PubMed1997

Dopaminergic projection to the septum mediates facilitatory effect of angiotensins on recognition memory in rats.

We have previously reported that the dopaminergic projection from A10 ventral tegmental neurons to the central amygdala is, in part, responsible for the facilitatory effect of angiotensin II (AII) and its 3-7 fragment [AII(3-7)] on the retrieval of information in memory motivated affectively and also on recognition memory. In this study, the influence of both angiotensins, given intracerebroventricularly at the dose of 1 nmol each, in rats lesioned with 6-OHDA to the nucleus accumbens septi (NAS) and to the nucleus septi lateralis (NSL) on recognition memory was evaluated. AII and its 3-7 fragment significantly improved object recognition in sham-operated to NAS and to NSL groups of rats. Bilateral 6-OHDA lesions to NAS totally abolished and to NSL significantly attenuated the facilitatory effect of both angiotensins on object recognition. These results suggest that the dopaminergic projection arriving to the septal structures. NAS and NSL takes part in the facilitatory effect of angiotensins on recognition memory.

Angiotensin II↗
PubMed1997

Behavioral activity of 1S,3R-ACPD, an agonist of metabotropic glutamate receptors.

The influence of intracerebroventricular (i.c.v.) injections of 1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD), an agonist of metabotropic glutamate receptors, on the activity of the central nervous system was examined in rats. 1S,3R-ACPD at the i.c.v. doses of 100 and 200 nmole significantly decreased apomorphine-induced stereotypy, and at a dose 200 nmole significantly diminished catalepsy caused by haloperidol, two behavioral symptoms controlled mainly by central dopaminergic system. The tested compound had no influence on the locomotor and exploratory activity of rats estimated in open field. 1S,3R-ACPD significantly improved acquisition at the i.c.v. dose of 100 nmole, and consolidation of information at the i.c.v. doses of 100 and 200 nmole. The tested compound had no influence on retention processes in passive avoidance situation. This compound also did not improve recognition memory tested in the object recognition test. These results indicated that 1S,3R-ACPD improved memory motivated affectively but had no influence on recognition memory and the diminished dopaminergic transmission.

Animals↗
PubMed1996

The effect of cholecystokinin (CCK-33) and C-terminal fragments of cholecystokinin: CCK-8 and CCK-4 on the cardiovascular system in rats.

1. The effects of cholecystokinin (CCK-33) and its fragments CCK-8 and CCK-4 on arterial blood pressure and the function of isolated rat heart and the amount of catecholamines in plasma, heart tissue were studied. 2. The results indicated that shortening of CCK to CCK-8 and CCK-4 eliminates the circulatory effect of this peptide. 3. A correlation was found between the results of in vivo and in vitro experiments and the amount of catecholamines.

Animals↗
PubMed1996

Cholecystokinin (CCK) and C-terminal fragments of CCK: effects of CCK-33, CCK-8 and CCK-4 in the cardiovascular system of diabetic rats.

The effect of cholecystokinin (CCK-33) and its fragments, CCK-8 and CCK-4, on arterial blood pressure and the function of isolated rat heart and catecholamine levels in plasma and from isolated heart tissue in diabetes mellitus were studied. The results indicated that, in diabetes, cardiovascular effects of CCK-33 and CCK-8 are diminished or abolished. Diabetes can change the response of the alpha- and beta-adrenergic system to CCK-33 and CCK-8 and the contents of catecholamines in heart tissue.

Animals↗
PubMed1996

Endoproteinase activities in wheat leaves upon water deficit.

In wheat leaves acclimated and non-acclimated to water deficit the azocaseinolytic activities of endoproteinases were increased about 7-fold under drought conditions. Under such conditions both the pH dependence profile and the endoproteinase pattern were also changed. The predominant contribution of serine proteinase (about 50% of total endoproteinase activity) remains unaltered in the drought stressed leaves. Cysteine proteinase was induced to the same extent in the drought-stressed leaves irrespective of the acclimation pretreatment, while the contribution of aspartic proteinase was reduced upon water deficit but in the acclimated stressed leaves was as high as in the non-stressed leaves. These changes in the pattern of endoproteinases seem to imply that the water deficiency affects endogenous proteolysis.

Endopeptidases↗
PubMed1996

Solcoseryl stimulates behavioural activity of rats.

The influence of Solcoseryl (S), a protein-free extract of calves' blood given intraperitoneally (i.p.) on the behavioural measures of activity of the central nervous system of male Wistar rats was examined. The drug (1.0 ml/kg i.p.) given 60 min before testing the animals in electromagnetic motimeter significantly enhanced overall and vertical motility of rats. S at the doses of 0.5, 1.0 and 2.0 ml/kg did not significantly influence the activity of rats in "open field". 1.0 ml/kg of S given 15, 45 and 60 min before thiopental (30 mg/kg i.p.) did not change the onset and time of sleep following the latter drug, except for the significant shortening of the time of sleep of animals injected with S 15 min before thiopental. S at the dose of 1.0 ml/kg did not change stereotypies produced by apomorphine (2.0 mg/kg i.p.) and amphetamine (6.5 mg/kg i.p.) but decreased intensity of haloperidol (1.0 mg/kg i.p.) catalepsy.

Actihaemyl↗
PubMed1996

The effect of pentagastrin, cholecystokinin and their analogues on rat arterial blood pressure and isolated heart.

The influence of pentagastrin (PG) and its analogues: 3-leupentagastrin (3-leu-PG), 4-AspOBzl-pentagastrin (4-AspOBzl-PG), and of the cholecystokinin -terminal tetrapeptide (CCK-4) and its analogue CCK-4(Phet) on rat arterial blood pressure and isolated heart were studied. 4-AspOBzl-PG and CCK-4 (Phet) had no effect on the arterial blood pressure or the isolated heart. PG (1.0 microgram/kg iv), slightly raised the systolic and diastolic arterial blood pressure, whereas 3-leu-PG (1.0 microgram/kg iv) slightly lowered the systolic arterial blood pressure. 3-leu-PG (0.1 microgram/0.1 ml), like PG (0.1 microgram/ 0.1 ml) increased the contraction amplitude of the isolated heart and had no effect on the heart rate, but unlike PG, it had no effect on coronary outflow. CCK-4 (1.0 microgram/kg iv) slightly raised the systolic arterial blood pressure but, unlike cholecystokinin had no effect on the isolated heart. We conclude that shortening of the CCK chain to a C-terminal tetrapeptide reduces the positive inotropic effect. Blocking of one of the aspartic acid carboxyl groups by a benzyl radical in the 4 PG position eliminates the PG effect on the circulatory system. Substitution of metionine for leucine at the 3-PG position reduces the PG action on the circulatory system.

Animals↗
PubMed1996

Behavioural activity of angiotensin II (3-7)4Phe--analogue of natural fragment 3-7 of angiotensin II.

A study was made of the influence of pentapeptide 3-7 angiotensin II [AII(3-7)], its analogue 3-7(4)Phe [AII(3-7)4Phe] and angiotensin II (AII) on the behaviour of adult male rats. The motility, stereotypy, spatial performance, learning of conditioned and passive avoidance responses allowing to avoid aversive stimulation were estimated. Examined peptides at the dose 1 nmol injected intracerebroventricularly 15 min before the experiment did not produce specific changes in psychomotor activity in the "open field" test and in retention of the spatial task in the Morris water maze. The rate of acquisition of conditioned avoidance responses was stimulated by AII(3-7)4Phe, AII(3-7) and AII administration. In the passive avoidance situation AII improved retention of the responses whereas analogue AII(3-7)4Phe and fragment 3-7 caused similar though less pronounced effect. All the peptides applied immediately before the experiment intensified stereotypy, a behaviour evoked by of apomorphine-1 mg/kg and amphetamine-7.5 mg/kg intraperitonealy injection. These results show similar psychotropic activity of analogue AII(3-7)4Phe, comparable with the activity of natural fragment 3-7 of angiotensin II.

Analysis of Variance↗
PubMed1996

The NMDA and GABA-A receptors in behavioral activity of rats.

The effects of bicuculline (0.25 mg/kg ip) and AP-7 (5 nmols icv) on the processes of retrieval, consolidation of conditioned reflexes, object recognition and locomotor activity were tested in rats. AP-7, bicuculline and AP-7 with bicuculline increased (but not significantly) locomotor and exploratory activity in the open field test. Only coadministration of AP-7 with bicuculline facilitated retrieval of passive avoidance in rats, but was without effect on consolidation in this test. AP-7 or bicuculline also did not influence on consolidation, when they were given alone. Object recognition was impaired (but not significantly) in groups of rats treated with bicuculline and bicuculline with AP-7.

2-Amino-5-phosphonovalerate↗
PubMed1996

The role of NMDA receptors in central action of angiotensin II.

The influence of noncompetitive (MK-801), competitive (AP-7) and the antagonist of polyamines site of NMDA receptor (arcaine) on the central activity of angiotensin II (A II) was studied. The open field test, conditioning of active avoidance responses (CARs) and passive avoidance situation was used to investigate learning and memory in rats. All used antagonists decreased beneficial action of A II on these processes.

Angiotensin II↗
PubMed1996

The estimation of interactions between arginine-vasopressin (AVP) and NMDA receptors in memory and learning processes.

Arginine-vasopressin (AVP) is a neuropeptide which facilitates learning and memory processes. We examinated the participation of NMDA receptors in beneficial effects of peptide. The results of our study show that noncompetitive antagonist of NMDA receptor-MK-801 impairs the effect of AVP on the consolidation of conditioned avoidance responses and antagonist of polyamines site-arcaine reduced advantageous effect of AVP on the retrieval of memory in passive avoidance situation.

2-Amino-5-phosphonovalerate↗
PubMed1995

Angiotensin II and its 3-7 fragment improve recognition but not spatial memory in rats.

The effects of angiotensin II (AII), its 3-7 fragment [AII(3-7)] and the substituted 3-7 fragment [Leu-5,AII(3-7)] given intracerebroventricularly (ICV) at the dose of 1 nmole each, on spatial memory and recognition were tested. AII(3-7) increased while Leu-5,AII(3-7) slightly decreased session to session foot shock reinforced runtime to the goal in a complex 6 chamber maze. The animals treated with AII performed in the maze similarly to saline injected controls. Overall number of errors was unchanged in all peptide treated groups in comparison with the control group. Object recognition was significantly improved in all the peptide treated groups except for the Leu-5,AII(3-7) group. The results point to the facilitation of recognition and lack of influence on, or even attenuation of, spatial memory by AII and its 3-7 fragment. Leu-5,AII(3-7) caused similar though less pronounced effects.

Amino Acid Sequence↗